The present disclosure relates to an electronic apparatus, a power feeding method, and a power feeding system which can supply an electric power, for example, in a non-contact manner.
In recent years, a power feeding apparatus (such as a non-contact power feeding apparatus or a wireless power feeding apparatus) for supplying an electric power to a Consumer Electronics (CE) Device such as a mobile phone or a portable music player in a non-contact manner by utilizing electromagnetic induction, magnetic sympathetic resonance or the like has received attention. As a result, the charging is not started by inserting (connecting) a connector of a power source device such as an AC (alternating current) adaptor into (to) an apparatus, but the charging can be started by placing the apparatus on a tray type power feeding apparatus (charging tray). That is to say, the terminal connection becomes unnecessary between the CE device and the power feeding apparatus.
In the power feeding apparatus, since the charging is started by placing the CE device on the charging tray as described above, it is possible to lighten a burden imposed on a user. On the other hand, however, the power feeding apparatus involves a disadvantage that an object other than the device as an object of the charging, for example, a foreign object such as a ten-yen coin (foreign object metal) is readily placed on the charging tray. When such a foreign object metal is placed on the charging tray, there is the possibility that the foreign object metal is heated. In particular, when the foreign object metal is wedged between the tray and the CE device, the temperature in this case becomes higher than that in the case where the foreign object metal is merely placed.
Then, heretofore, for the purpose of taking measures such that the charging is stopped when there is such a foreign object metal, and so forth, various kinds of techniques for detecting the foreign object metal on the charging tray have been proposed. For example, there has been proposed a technique for detecting a temperature of an object placed on the charging tray, and judging that the object is a foreign object when an abnormal temperature rise is confirmed. This technique, for example, is described in Japanese Patent Laid-Open No. 2008-172874 (referred to as Patent Document 1 hereinafter). In addition, there has also been proposed a technique for charging a load so as to follow a predetermined pattern, thereby detecting an over-load. This technique, for example, is described in Japanese Patent Laid-Open No. 2002-34169 (referred to as Patent Document 2 hereinafter).